CNC At Home: Machining Aluminum with a Tormach PCNC 1100

Unlike 3D printing, machining applies substantial lateral loads on parts: clamps, vises, and other workholding methods are crucial — and ingenuity is key. This “two-setup” job was able to be done in one setup by moving clamps midway through the cutting operation.

Video Overview:

We start off by importing and orienting the part prior to creating the CAM operations – this is where we choose what cutting tools (drills, end mills, etc) to use.

Excess Material Tips

In volume production the material for this job would be waterjet cut to avoid unnecessary machining, but that's not practical for one-off jobs. You could still rough-cut some excess material away with a bandsaw, but for this job, I chose to machine it away.

Use larger, roughing cutters to rapidly remove material, then clean up with higher quality “finish” end mills.

Use CAM simulation to evaluate the job prior to running on machine! (6:00 minutes into video).

Sacrificial Layer Tips

At 8:45 into the video, we have moved on from the programming and are now working with our raw materials. I want to clamp the material directly to the mill, but need to use a “sacrificial sub plate” to ensure the machine does not cut into the machine table. At 10:10 we use a small benchtop sheer to cut some aluminum to make this plate.

Aluminum and plastic can all make great, inexpensive sacrificial sub plates. Wood can work as well but some woods will expand with moisture (e.g. flood coolant), so factor that in as applicable.

Aluminum extrusions often have bow in them – keep this in mind when you decide which side faces up, how the part is clamped, and where you set you “Z” axis “zero” point (a.k.a. height offset). At 16:00, we discus clamping and cut strategy, then at 19:45 we are making chips! We swap the clamps at 28:30 – this lets us complete the whole part without having to reindicate our “zero” which helps ensure perfect tolerances. Then some final part cleanup before shipping off to customer.

Machining Videos

CNC At Home: Machining Aluminum with a Tormach PCNC 1100

Unlike 3D printing, machining applies substantial lateral loads on parts: clamps, vises, and other workholding methods are crucial — and ingenuity is key. This “two-setup” job was able to be done in one setup by moving clamps midway through the cutting operation.

Video Overview:

We start off by importing and orienting the part prior to creating the CAM operations – this is where we choose what cutting tools (drills, end mills, etc) to use.

Excess Material Tips

In volume production the material for this job would be waterjet cut to avoid unnecessary machining, but that's not practical for one-off jobs. You could still rough-cut some excess material away with a bandsaw, but for this job, I chose to machine it away.

Use larger, roughing cutters to rapidly remove material, then clean up with higher quality “finish” end mills.

Use CAM simulation to evaluate the job prior to running on machine! (6:00 minutes into video).

Sacrificial Layer Tips

At 8:45 into the video, we have moved on from the programming and are now working with our raw materials. I want to clamp the material directly to the mill, but need to use a “sacrificial sub plate” to ensure the machine does not cut into the machine table. At 10:10 we use a small benchtop sheer to cut some aluminum to make this plate.

Aluminum and plastic can all make great, inexpensive sacrificial sub plates. Wood can work as well but some woods will expand with moisture (e.g. flood coolant), so factor that in as applicable.

Aluminum extrusions often have bow in them – keep this in mind when you decide which side faces up, how the part is clamped, and where you set you “Z” axis “zero” point (a.k.a. height offset). At 16:00, we discus clamping and cut strategy, then at 19:45 we are making chips! We swap the clamps at 28:30 – this lets us complete the whole part without having to reindicate our “zero” which helps ensure perfect tolerances. Then some final part cleanup before shipping off to customer.

Driving Big Stepper Motors with Arduino

Any stepper motor is great, but the big ones are amazingly impressive. There are numerous stepper drivers dedicated for use with Arduino, but they are generally limited to Nema 17 and Nema 23. Luckily, using larger steppers (Nema 34 in this instance) with Arduino is still easy. Large steppers give you an amazing combination of precision, control and torque that can be useful for anything from home automation to DIY CNC machines. In these two videos, we walk through the setup of the motor, driver, and Arduino.

Part 1: Test Code, Increase the Load

In this video we test code from three different Arduino programs to drive the large NEMA 34 stepper, then increase the load on the shaft to see how the stepper handles the additional weight.

Part 2: Fabricate a Steel Plate

In the next video, we fabricate a test plate in the machine shop to test the motor speed and responsiveness, experimenting with what works and doesn’t. We machine a 0.75" hole in a ~7LB, 15" 1/4 inch steel plate, then turn a bushing which will let us secure the plate to the stepper D-shaft.

Circuit, BOM and Code

How to Wire the Circuit

microstepping driver ST-M5045

Pul+ goes to +5V

Pul- goes to Arduino Pin 9

Dir+ goes to +5V

Dir- goes to to Arduino Pin 8

Enable+ to nothing

Enable- to nothing

Bill of Materials

Code Examples

Download the Arduino Sketches
The Nema34_Arduino code examples include using a potentiometer to control the speed as well as a program to test how quickly the motor can stop. Both programs use the AccelStepper Arduino library.

I'm no expert on this subject matter and am anticipating (hoping!) others may have comments with even better hardware or software tips and tricks — but in the meantime there doesn't seem to be much content on YouTube on driving large steppers with Arduinos, and I've had quite a few email inquiries about it, so here it is!

Anatomy of a CNC Mill

Chris the Carpenter from Rocket Brand Studios is no stranger to CNC milling. He built his own industrial strength CNC mill, which he uses to make tools and parts for his robotics business

In this video, Chris walks you through the basics of a CNC mill's anatomy, including all the major hardware and software components. He also gives some advice on building your own CNC, and even some eBay shopping tips. Watch the video to learn more about:

Linear Bearings and Ball Screws

Stepper Motors

Controllers

Cutter heads and Spindles

Cooling and Dust Removal

Chris has built some amazing things on his mill, including this masterpiece. You can also find Chris' robot kit in the Maker Shed.

Bicycle-Powered Treehouse Elevator

Ethan Schlussler of Sandpoint, Idaho, built this clever bicycle-powered treehouse elevator to make it easier to reach his nearly 30-foot-high treehouse.

"I got tired of climbing a ladder six and a half million times a day, so I made a bicycle powered elevator to solve this problem," he writes.

"It was originally a 20-something speed bicycle, but first gear wasn't slow enough, so I cut the large sprocket off the front, and welded it on the rear to get a lower gear. I also had to do away with the de-railers and make a new chain tensioner."

The treehouse is not yet complete, but Ethan says, "I will be building walls and insulating it in the next few weeks, and eventually I intend to live (or at least sleep) in it. "

A heavy chain keeps the bicycle from being pulled up by the counterweight.

DiResta: Skull Ring

Jimmy wants a ring that makes an impression. Jimmy gets out the wax, a hobby knife, and a Dremel tool and sets to work.

In each bi-monthly episode of DiResta (every other Wednesday at 2pm PT), artist and master builder Jimmy DiResta ("Dirty Money," "Hammered," "Against the Grain," "Trash for Cash") lets us into his workshop, to look over his shoulder while he builds whatever strikes his fancy.

DiResta: Heart Key

In this episode of DiResta, Jimmy gets all sentimental and makes a heart key for a particularly big-hearted friend.

In each bi-monthly episode of DiResta (every other Wednesday at 2pm PT), artist and master builder Jimmy DiResta ("Dirty Money," "Hammered," "Against the Grain," "Trash for Cash") lets us into his workshop, to look over his shoulder while he builds whatever strikes his fancy.

For more details on the build, check out the MAKE post: http://blog.makezine.com/2012/10/03/diresta-heart-ring/

And look for new episodes of DiResta every other Wednesday at 2pm Pacific/5pm Eastern.

Meet the Makers: Satya Kraus

Learn how Satya Kraus felt when he saw a motorcycle for the first time in his life. Since that moment, he has been obsessed, and turned that obsession into Kraus Motor Co. He hand-builds the most incredible machines from scratch in his workshop under the redwoods.